Cardiac cycle isovolumic relaxation t wave relaxation

Info icon This preview shows pages 73–94. Sign up to view the full content.

View Full Document Right Arrow Icon
Cardiac Cycle Isovolumic Relaxation T-wave Relaxation LVP decreases Once LVP< AP Aortic valve closes Both valves closed No movement of blood
Image of page 73

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Cardiac Cycle LVP still decreasing Once LVP< LAP Mitral valve opens Blood moves into ventricle - filling
Image of page 74
75 Cardiac cycle:
Image of page 75

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
76
Image of page 76
Stroke Volume Stroke Volume (SV) = amount of blood pumped in 1 beat SV=EDV-ESV Average Stroke Volume = 70 mL Depends on Contractility and Venous Return
Image of page 77

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Summary of Factors Affecting Stroke Volume: 78
Image of page 78
Stroke Volume Venous return is affected by Skeletal muscle pump Respiratory pump Sympathetic innervation Contractility affected by Epi / Norepi Length of muscle fibres of the heart
Image of page 79

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Frank-Starling Law of the Heart Preload – filling of the heart Greater filling or preload means greater stretch of the myocardium and then a greater force of contraction. 80
Image of page 80
Frank-Starling Law Stroke volume increase as EDV increases Whatever goes in – goes out the next beat Figure 14-28
Image of page 81

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 82
Figure 12.25
Image of page 83

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Inotropic Effect The effect of norepinepherine on contractility of the heart Figure 14-29
Image of page 84
Stroke Volume
Image of page 85

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
bind to that activate resulting in phosphorylation of 1 -receptors Epinephrine and norepinephrine cAMP second messenger system Ca 2+ removed from cytosol faster Shortens Ca-troponin binding time Ca 2+ stores in SR Shorter duration of contraction More forceful contraction Phospholamban Ca 2+ -ATPase on SR Ca 2+ released Ca 2+ entry from ECF Open time increases SR = Sarcoplasmic reticulum ECF = Extracelllular fluid Voltage-gated Ca 2+ channels KEY Catecholamines Modulate Cardiac Contraction Figure 14-30
Image of page 86
Cardiac Output Cardiac Output (CO) = amount of blood pumped per minute Cardiac Output = Stroke Volume x Heart Rate Average Cardiac Output = 5 L
Image of page 87

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Cardiac Output Determined by heart rate times stroke volume
Image of page 88
Stroke Volume and Heart Rate Determine Cardiac Output Figure 14-31 determined by is influenced by which varies with is a function of increases increases determined by CARDIAC OUTPUT aided by Heart rate Due to parasympathetic innervation Sympathetic innervation and epinephrine Venous return Venous constriction End-diastolic volume Rate of depolarization in autorhythmic cells Stroke volume Contractility Respiratory pump Skeletal muscle pump Decreases Increases Force of contraction in ventricular myocardium
Image of page 89

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Effects of Exercise Body’s demand for oxygen and blood flow increases Cardiac Output must increase (by up to 5 X) Body does this by increasing Stroke Volume By increasing contractility Heart Rate Sympathetic Tone – Epinephrine (Adrenalin)
Image of page 90
Figure 19.8 Venous return Exercise Contractility of cardiac muscle Sympathetic activity Parasympathetic activity Epinephrine in blood EDV ESV Stroke volume (SV) Heart rate (HR) Cardiac output (CO = SV x HR Activity of respiratory pump (ventral body cavity pressure) Activity of muscular pump (skeletal muscles) Sympathetic venoconstriction BP activates cardiac centers in medulla Initial stimulus Result Physiological response
Image of page 91

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Heart Muscle Metabolism: Heart muscle is highly oxidative abundant mitochondria and myoglobin Gets oxygen from coronary circulation 92
Image of page 92
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern